What you always suspected is true: Lawyers really are different from everybody else. At least that’s what psychologist Lawrence Richard has found from almost two decades of administering personality tests to thousands of lawyers.

The Myers-Briggs Type Indicator, for instance, divides people into 16 basic personality types. But lawyers overwhelmingly fall into just five of these, says Richard. And it isn’t law school that molds them into such a distinct group. It’s the other way around: Their personalities lead them to the law. The most dominant trait shared by lawyers is that they enjoy intellectual stimulation, says Richard, who himself gravitated to the law, working as a trial lawyer for ten years before getting a Ph.D. in organizational behavior and going to work for the consulting firm Altman Weil, Inc. He’s typically hired by dysfunctional law firms or in-house departments to help with specific problems like low retention or poor morale. He is also retained to help develop strategic planning, leadership, and teamwork skills. The second most common personality trait among lawyers, he says, is that they’re more introverted than extroverted. “Among the general public, extroverts consistently outnumber introverts, but among lawyers it’s just the opposite. In every law firm we’ve measured, introverts are in the majority,” says Richard. “Lawyers like time to process and think.” And, he says, there is no significant difference in the data between in-housers and those practicing in firms.